Rectifier anode



April 21, 193.6.` c, K, MART, 2,038,491

RECTIFIER ANODE Filed Jan. 25, 1954 '3 sheets-sheet 1 Si? @MM5 April 21, 1936. o. K, MARTI RECTIFIER ANoDE 3 sheets-sei l2' n Filed Jan. 25, 1934 A.. a@ Y A y m; f.; w W Zw a wwf y@ n" f April 2l, 1936.4

o. K. MAR-n REGT'IFIER ANODE Filed Jan. 25, 1934 s sheets-sheet 5" scription when read in connection with theA ac-V 55 c Patented pr. 21, 1936 UNITED STATES PATENT yOFFICE f RECTIFIER AN ODE Application January 25, 1934, Serial No. 708,208

5 Claims.

This invention relates to improvements in the electrodes of electron discharge devices and more particularly to means for controlling the attachment of the electron discharge to the discharge receiving electrode of such device.

In an electron discharge device, the path between the electron emitting electrode and the electron receiving electrode does not include the entire area'of the electrodes available for either emitting or'receiving electrons. The flow of the electron discharge causes a large amount of heat to be produced at the contact points between the discharge and the electrodes, thus Vtending to cause deterioration of the electrodes or to produce excessive amounts of metallic Vapor and also cause release of the gases or vapors occluded in the electrodes, thus increasing the vapor pressure within the device which tends to impair the op'- eration of such device. The particular areas to which the discharge will attach on the electrode is determined by the relative position of the 'electrodes, by the unobstructed space available for the arc discharge and by the absence or presence of magnetic materials in or adjacent to the discharge path. If the discharge is forced to travel at a high velocity in the space adjacent the electrodes, the point of attachment of the discharge will likewise travel over the entire available electrode surface thereby insuring even distribution of the heat generated by such attachment throughout the entire electrode.

It is accordingly an object of the present invention to provide an electron discharge device electrode in which the point of attachment ofk the discharge to the electrode is forced to move over the surface area of such electrode during the period of such attachment. Y

Another object of the'present invention is to provide an electrode for electron discharge devices of the vapor arcing type in which the point of attachment of the arc to the electrode is continuously moved over the surface of the electrode in a circular path due to the action of magnetic means associated with the electrode.

Another object of the invention is to provide an electrodefor electron discharge devices with internal magnetic means operable in response to the flow of current through such electrode to cause movement of the point of attachment of the discharge over they entire surface area of the electrode.

Objects and advantages other than those above described will be apparent from the following decompanying drawings, in which (Cl. Z50-27.5)

Fig. 1 is a vertical cross-sectional view of an electrode construction for use in an electron discharge device of the vapor arcing type and which embodies the present invention;

Fig. 2 is a partial vertical cross-sectional View of a modified embodiment of an electrode head construction differing only in its structural details from the embodiment illustrated in Fig. 1;

Fig. 3 is a horizontal cross-sectional view, taken on the plane II-II of the embodiment illustrated in Fig. 2; Y

Fig. 4 is a partial vertical cross-sectional view of a modified embodiment of an electron receiving electrode construction in which a modified construction of magnetic means for causing move- 15 ment of the point of attachment of the electron discharge is illustrated; and

Figs. 5, 6 and 7 are embodiments similar to the embodiment illustrated in Fig. 4, but differing in the arrangement and construction of the magnetic means for causing movement of the discharge over the surface of the electrode Y Referring more particularly to the drawings by characters of reference, the reference numeral I I designates a portion of a casing for an electron discharge device of the vapor arcing type such as are well known in the art and therefore do not require detailed showing in their entirety. A hollow skirted insulator I2 extends through an aperture in the casing I I and is supported thereon by a. piece I3 secured to such casing or by other suitable means. The insulator is sealed into the aperture in casing II by means of a gasket I4 or by other suitable means well known to the art. The stem I6 of an electrode extends through insulator I2 in spaced relation therewith and the head, to be specifically described hereinafter, of the electrode abuts against one end of the insulator. The electrode head is held betweenthe one end of the insulator I2 and an insulation washer I1, resting onV a ange I8, ,by compression of a spring 2I between the other end ofV the insulator and a nut 22 threaded on the stem I6. The spring compensates for the difference between coeiiicients of expansion of the several materials employed in the electrode construction and maintains mechanical contact and sealing engagement of the electrode head with the insulator. An arc guide or sleeve 23 Vis supported from a skirt of the insulator I2 50 and depends therefrom about the lower end of the insulator and the electrode head.

The electrode head is preferablyvformed in two portions 2G and 21, with the side wall portion 26 clamped between the end of the insulator I2 and 55 the flange I 8v of the electrode stem I6 and the end or face portion 21 of the electrode head is screw threaded or otherwise attached to the portion 26 as will be described hereinafter. The twoportions of the head may be made of any Suitable conductive but preferably non-magnetic material and enclose a space within which is arranged a coil 28 of edge wound highly conductive magnetic material. The several turns of the coil are insulated from each other by insulation 29I arranged and retained between such turns. Ihe inlet or stem end of the coil is secured to the flange I8 by means of studs 32 and 33 and the outlet or head end 34 of the coil is secured to the electrode head. Current flowing through the stem I6 must therefore flow through the'coil 23 to reach the head 26, 21. Such current creates a radial magnetic eld about the coil and the head which causes an arc attaching tothe head to move in a circular path over the surface, thereof. Due to the present construction, a suflicient number of `turns of the coil 28"are present within the space enclosed by the head to insure movement of the point of attachment of the arc at such speed as to revolve such point over the entire heat at least once during each one-third cycle of the alternating current supply voltage which is Ythe working period of anr electron receiving electrode when the discharge device is used as a rectier in the usual rectifying connections. The end portion 21 of the electrode head is preferably made concave to lengthen the path and thus to prevent attachment. of the arc to the central portion thereof wherev the magnetic field would be relatively ineffective to cause rotation of such arc.

In the modification illustrated in Figs. 2 and 3, the inlet end 35 of the coil 28iswelded to a boss 36 extending from the flange' I8 of the electrode'stem I6. The outlet end of the coil is divided into a plurality of ears or lugs 31 bent over the electrode stem flange I8 and insulated from the flange by gaskets 38and 39. The ears 31 are preferably formed only over the half of the periphery of the electrode head farthest from the electron emitting electrode of the device and are in contact with such one-half portion of the head portion 26. Currentrcan therefore'flow only from the stem I2 through the boss 36, the coil 28, the ears 31 and the electrode headV portion 26 to the head portion 21; Any tendency for the arc to attach only on the side of the electrode nearest the electron emitting electrode is thus counteracted by the resistance in the head material from the point of contact of the ears 31 through the head portions 26 and 21 to the nearer side of such head. The arc is, of course, caused in addition to revolve over the head portion 21 by the rotating of eld produced by the coil 28 as is described above.

The embodimentY illustrated in Fig. 4 differs from the previously illustrated and described embodiments in anumber of structural details. The head portion 21 in Fig. l is formed with a concavity of greater degree than was heretofore illustrated. The inlet end 35 of coil 28 extends adjacent the concavity of the head and is secured to the electrode stem I6 by a stud 33 as in Fig. l. The several turns of coil 28 are'formed of material substantially square in cross-section and are insulated from each other and spaced from the head portions 26 and 21. The coil is again provided'withears or lugs 31 arranged asr and for the purpose set forth above relative to the construction illustrated in Figs. 2 and 3.

In the modied embodiment of the invention illustrated in Figs. 5, 6 and '7, the coil 28 is wound flatwise, the inlet end 35 of the coil 28 being welded to a ring 4I secured to the stem I6 by a stud 33. The outlet end of the coil is formed as a screw threaded cylinder 42 which is of such length in Figure 5 as to form the only means by which the head portions 26 and 21 are connected. The head is held between the stem flange I8 and the end of the insulator I2 as illustrated in Fig. 1. The coil 28 in the three embodiments now under consideration rests on an insulating plate 43 arranged inthe bottom of the space enclosed by the head. In Figs. 6 and 7 the entire electron receiving surface of the head is made as an integral, member 44. The head 44 is screw threaded to the cylinder outer coil end 42. In Fig. 6 the outer coil end 42 is also internally screw threaded for attachment to a head portion 46 clamped between the stem flange I8 and the end of the insulator I2. In Fig. '1A the outer coil end 42 is weldedor otherwise xedly secured to a portion of a split ring 41 which, with the head portion 46, is clamped between the stem flange I8 and the endof the insulator I2 aspreviously described.

In operation, the. discharge within the device is initiated and maintained by any means known in the art. Upon positiveenergization ofthe electrode illustrated, current will flowY through the stem I6 through the coil 28 and through theV head portion. securedto the outer. end of the coil.

Such current will ow continuously into the spacev between the electron. receiving and-the electron emitting electrode (not shown) in the form of a discharge which concentrates on azportion of the edge of the head portion 21. The flow of current throughthe coil 28 produces amagnetic field in.

which the lines of courseY are substantially. parallel within the anode head andare divergent at the bottom portion.. of such head to form a eld having a radial component, close themselvesv in the spaceabout thea-node head. The dischargeintersects the lines efforce and is therefore driven ina-direction tangential to the surface of the lowerY portion of the'anode. The discharge will therefore move in a circular path and the point of attachment of such discharge on the head ofthe electrode will move in a circular path over such surface for the entire period of time during whichl the. dischargeis taking place. The velocity of the movement of the point of attachment of the dischargecnthe electrode is. determined by the current intensity and the intensity cf` the magnetic eldproduced about the. coil 28. Instead of beingconcentrated on only a portion of the electrode head, the pro-V duction of heatdue to such attachment ofy the discharge is distributedsubstantially uniformly over the entire area of the electrode. Deterioration of the electrode heador`v impairment of-'the internal conditions of the. discharge device by release of gases, bothqdeterioration of the head* and release of .gases beingduevto concentration of the attachment off the discharge' to 'a small portion of the area' of the head, is therefore prevented.

Although but a few embodiments of the present invention have been illustrated anddescribed, it Will be apparent to those skilledin the art that various changes and modifications may be made therein without departure from the; spirit' of the invention or from` the scope of the .appended claims; 1

The lines of force t is claimed and desired to secure by Letters Patent;

1. An electron receiving electrode for an electron discharge device comprising a hollow insulator, a metallic stem extending through said insulator and having an enlarged ange portion, an electron receiving shell clamped between said insulator and the flange portion of said stern and insulated therefrom, and a solenoid arranged wholly within said shell and connecting said stem with said shell to provide the only path for current flo-w therebetween.

2. An electron receiving electrode for an electron discharge device comprising a hollow insulator, a metallic stem extending through said insulator and having an enlarged flange portion, an

electron receiving shell divided into a. plurality of portions and clamped between said insulator and the flange portion of said stern,r an insulating member arranged between the iiange of said stern and said shell, and a solenoid arranged wholly within said shell and connecting said stem with said shell to provide the only path for current flow therebetween.

3. An electron receiving electrode'for an electron discharge device comprising a hollow insulator, a metallic stem extending through said insulator and having an enlarged flange portion, an electron receiving shell clamped between said insulator land the ange portion of said stem, and

a solenoid formed from material of rectangular cross section and formed with the greater dimension arranged horizontally and connecting said stem with said shell to provide the only path for current ow therebetween.

4. An electron receiving electrode for an electron discharge device comprising a hollow insulator, a metallic stem extending through said insulator and having an enlarged flange portion, an electron receiving shell clamped between said insulator and the flange portion of said stem, and a solenoid formed from material of rectangular cross section and formed with the greater dimension arranged vertically and connecting said stem with said shell to provide the only pathl for current flow therebetween.

5. An electron receiving electrode for an electron discharge device comprising a hollow insulator, a metallic stem extending through said insulator and havin-g an enlarged ange portion, an electron receiving shell, an insulating member arranged between the flange of said stem and said shell, resilient means cooperating with said insulator and said stem to clamp said shell between said insulator and said insulating member, and. a solenoid arranged Wholly within said shell and connecting said stem with said shell to provide the only path for current flow therebetween.

OTHMAR K. MARTI. 

